The family of the detained former South African National Defence Force (Sandf) who was sentenced to death in South Sudan, is concerned about his health.

More than one month has passed since colonel William Endley was sentenced to death in Juba.The 55-year-old was charged with espionage and conspiring to overthrow the Kiir government.

Endley was working in 2016 as an adviser to former first vice president turned rebel leader Riek Mahar. The South African national was arrested in the capital Juba by national security agents on 18 August 2016.

Endley's sister, Charmaine Quinn, told eNCA that her brother was not doing well health-wise in Juba.

The South African woman further said she had not heard anything regarding the appeal to the South African government.

Quinn explained that she wrote to South African President Cyril Ramaphosa and Department of International Relations and Cooperation Minister Lindiwe Sisulu to try and get the government to see the injustice of this sentence.

Quinn said she had full faith in the South African government.